Immunization efforts had all but eliminated childhood diseases such as polio, measles, and mumps by 1990, but the rapid introduction of new vaccines may paradoxically be promoting reemergence as complex injection schedules decrease compliance by parents and physicians. Vaccine manufacturers have responded with multivalent vaccines that provide single-injection protection against multiple agents. In addition to the measles, mumps and rubella vaccine (MMR), pentavalent combinations of diptheria toxoid, tetanus toxoid, and acellular pertussis (DTaP), inactivated polio virus (IPV), Haemophilus influenzae Type b (Hib), and/or hepatitis B (HepB), have been approved and others remain in development. The increasing range and multivalency of vaccines has created a need for cost-effective, highly multiplexed serological testing to determine antibody response to each component. New tests are needed both as screening assays to evaluate protection of each patient and as a tool for vaccine development to detect efficacy for each target in novel combinations. The traditional multiwell ELISA format immunoassay is laborious and poorly matched to multianalyte testing. Flow cytometric bead array immunoassays can replace such ELISA format assays with a miniaturized, multiplexed, rapid, sensitive and specific alternative. Despite the commercial potential of bead arrays for serology to monitor vaccination and infection, this market remains undeveloped compared to multiplexed sandwich immunoassays such as cytokine panels. A key limitation is the need to coat beads with diverse antigens, including proteins, polysaccharides, and whole virus particles, which requires a wide range of immobilization chemistries that must be independently optimized. Insofar as a comprehensive vaccination and infection assay will require >50-plex testing, the challenge of preparing robust and reproducible bead panels is a significant barrier. This submission proposes to overcome the limitations of current assays and expand the potential of the bead array immunoassay by the development of protocols that allow rapid multiplexing of diverse antigens employing novel chemistries and assay design to coat beads independent of whether the antigen is a carbohydrate, protein or virus. This will lead to kits for screening for responses to the full range of approved vaccines and for exposure to the most common infectious organisms. Importantly, these kits are completely dynamic and can be modified to reflect new vaccines, new infectious disease serotypes and/or newly discovered disease organisms. This platform has the potential to be engineered for use in the third world. PUBLIC HEALTH RELEVANCE: Multivalent Vaccine Titer Test A standardized method to rapidly determine the level of response to multivalent vaccines has not been developed. Availability of a standardized test would allow more efficient development of new multivalent vaccines as well as determining effectiveness of vaccines in vaccinated children and adults. In this submission we propose the development of a platform technology that will allow rapid, cost effective and sensitive standardized testing for vaccine efficacy.